/* -*- Mode: C; c-basic-offset:4 ; -*- */
/*
 *
 *  (C) 2003 by Argonne National Laboratory.
 *      See COPYRIGHT in top-level directory.
 */
#include "mpi.h"
#include <stdio.h>
#include "mpitest.h"

/*
static char MTEST_Descrip[] = "Simple test of intercommunicator send and receive";
*/

int main( int argc, char *argv[] )
{
    int errs = 0;
    int leftGroup, buf, rank, remote_size, i;
    MPI_Comm comm;
    MPI_Status status;

    MTest_Init( &argc, &argv );

    while (MTestGetIntercomm( &comm, &leftGroup, 4 )) {
        if (comm == MPI_COMM_NULL) continue;

	if (leftGroup) {
	    MPI_Comm_rank( comm, &rank );
	    buf = rank;
	    MPI_Send( &buf, 1, MPI_INT, 0, 0, comm );
	}
	else {
	    MPI_Comm_remote_size( comm, &remote_size );
	    MPI_Comm_rank( comm, &rank );
	    if (rank == 0) {
		for (i=0; i<remote_size; i++) {
		    buf = -1;
		    MPI_Recv( &buf, 1, MPI_INT, i, 0, comm, &status );
		    if (buf != i) {
			errs++;
			fprintf( stderr, "buf = %d, should be %d\n", buf, i );
		    }
		}
	    }
	}
	/* Now, reverse it and send back */
	if (!leftGroup) {
	    MPI_Comm_rank( comm, &rank );
	    buf = rank;
	    MPI_Send( &buf, 1, MPI_INT, 0, 0, comm );
	}
	else {
	    MPI_Comm_remote_size( comm, &remote_size );
	    MPI_Comm_rank( comm, &rank );
	    if (rank == 0) {
		for (i=0; i<remote_size; i++) {
		    buf = -1;
		    MPI_Recv( &buf, 1, MPI_INT, i, 0, comm, &status );
		    if (buf != i) {
			errs++;
			fprintf( stderr, "buf = %d, should be %d\n", buf, i );
		    }
		}
	    }
	}
        MTestFreeComm(&comm);
    }

    MTest_Finalize( errs );
    MPI_Finalize();
    return 0;
}
